Sunday, January 29, 2017

All Information is Good Information!

Someone once told me that and I have firmly come to believe that. Not that the information in itself may be good; but it is good to know that certain individuals believe something (which maybe erroneous) that you now know where they stand. The other side of the good information is that you may be presented with thoughts or concepts that perhaps were unintended in what you personally have presented. An example is to merely say "hook it up" and run the test failing to mention that the test needs to be run with a dummy load. You know to hook it into a dummy load; but that may not be clear to others.

For three years now I have participated in a monthly podcast along with Bill, N2CQR who has been at it for 10 years and is one of the original founders. Check out Bill's blog http://soldersmoke.blogspot.com for a link to the latest podcast (#193). The subject matter of the blog --yep ham radio with an emphasis on homebrewing, current technical topics and a trip across our respective work benches to share projects we are building. I tend to favor the newer technologies (digital VFO's) and Bill likes the older type (Analog VFO's). We had thought this was a good approach as it offered our listeners a range of topics or how to perform a task using different technologies. (A comment here: I see Bill drifting more and more toward the "digi" stuff.)

Usually the podcast starts by Bill asking me what number is it -- and I respond much like the Rock Jock's of the 1960's by shouting with enthusiasm the current number. I guess I always wanted to be a rock jock --a dream of mine that was fulfilled by my daughter who actually was one!

Hopefully our format shares technical knowledge and even our tales of woe as we smoked parts and most importantly to include projects by our listeners. In fact Bill's blog is mostly about projects being built around the world with many of the projects directly relating to subjects covered in the podcast. At one time we ran a series about the Michigan Mite Mite a single transistor transmitter using colorburst crystals. Bill (mostly Bill) and I even supplied crystals to those wanting to build the project. We did supply about 50 crystals and we know of many being built using their own crystals. So we do think our efforts have been impactful across the world of ham radio.

The last several podcasts have highlighted a currently world wide popular ham transceiver known as the Bitx40. This amazing complete built 40 Meter SSB transceiver comes to you pre-built, delivered to your door for an amazing price of $59 --and that includes a digi LO and LCD display! Bill has built two and I have built one!

But the real thrill of this radio is the ability to customize the project and there is even a "hack page" provided by the manufacturer to collect these mods/improvements, to which both Bill and I have contributed. I have even created a series of web pages to assist the 1st time builder to get the Bitx40 on the air. You can find that here Bitx40 from N6QW We believe about 2000 of these radios are now in ham shacks across the globe. We have VU2ESE, Farhan to thank for this wonderful project and the idea of how to spread the ham radio gospel.

Two other recent technical highlights discussed reverse polarity protection and the use of active de-couplers to remove noise from audio circuit resulting from the use of OLED displays. Perhaps the message to us is that these were too simple technically to even merit a word let alone a discussion. Inputs like this would help guide a selection of topical discussions.

Since we do the podcast monthly at times it may stretch to five weeks and to alert the podcast fans Bill will send notice the various reflectors in essence saying "we're back at it." So was the case yesterday when SS #193 was announced to the world.

On one particular reflector there were several negative comments about the podcast including a derisive comment about my "wanna be rock jock announcing" of the podcast number. Further comments involved the lack of technical content and it not being very useful. That is good information! Unlike our current POTUS 45 we are not thin skinned about negative comments nor have we banned any listeners!

Instead what would be helpful is if listener's would share with us the good, the bad and the ugly! If my shouting into the microphone is offensive to many of the listeners then it is an easy fix. Just tell us. But if you laugh a bit while I say it --let me know. As to technical content let us know that too. If you would like to know about Hilbert transforms or how does a Double Balanced Mixer perform a commutating action to demodulate a signal --we can do that too. Although a treatise on 3rd order linear regression might lose a few listeners. But let us know. The podcast is for you not us!

So to those several hams that had the courage to input negative comments we salute you and say thank you. But we'd also like to hear from others who may share those same negative (or positive) feelings about what Bill and I do. Let me assure you will not be banned from the podcast nor will you have to show proof of license.

Thursday, January 26, 2017

Yes! Ham Radio Is a Very Small World!

As many who have read this blog for the last year or so know that my XYL is not in the best of health and as such we typically have a medical appointment almost every week. I literally have an autopilot button on my car's dashboard that says UCLA Healthcare Center, Thousand Oaks and boom we get there almost automatically.

This past Monday was no exception and the only exceptional thing is that we have been having a lot of rain the past several weeks and it was cold too! (Cold is relative at a mere 52 Degrees F.) Well at this time of year I love to wear my wool Beret as not only does it keep my head warm but also is a great chick magnet! The beret was not my headgear of choice on Monday since it was raining and my alternative was to wear my DX Engineering baseball cap. No I did not spend $9.95 and buy one; but it was sort of a consolation offering after DX Engineering screwed up an order of mine.

So yes it was really raining and the hat did keep my head dry and warm. Upon entering the facility we were met by Michael, a medical assistant, who has helped us before. Once we got in the exam room Michael says I see your hat with DX Engineering on it -- Are you a ham? Well it was a micro-second and I answered an affirmative yes and gave my call sign.

Well then Michael shares with me that he is soon to take the General Exam but his next stumbling block was what kind of a rig he could acquire while operating with a limited budget. As he was tending to my XYL, I wrote down my website, blog and the link to hfsigs.com to find out more about the Bitx40 which is an ideal entry level rig for the new ham. At $59 including shipping it is a real deal!

I wished him luck and told him he could contact me through the website or blog. I can't describe the gleam in his eye when I shared I was a ham and perhaps had an answer to his rig problem.

Saturday, January 21, 2017

Really Big (bigger) Displays the 240 X 320 Color TFT

About two years ago I bought several of the 240 X 320 displays and immediately was struck by how much information can be displayed on the face of the unit and like a choice of 256K colors. Lots of customization can be had here. Unlike the 128 x 128 or 128 X 160, which I used straight into the Arduino pins, these larger displays Do Not Like to see 5 VDC.

They like to see 3.3 VDC and typically a "Level Shifter" must be interjected between the 5 volt Arduino Pins and the pins on the display which like to see 3.3 VDC. So this is where I get emails about running the Arduino at 3.3 VDC and then no level shifting is required. Not sure my heart is that strong to do that. The literature abounds with tricks and tips to do the level shifting.

One method involves a series resistor combination of a 4.7K in series with a 10K (the 10K other end is at ground). Now to the high level math. If you ran 5 VDC through the 14.7K resistor( 4.7K + 10K) the current via ohms law would be 5/14.7K = .340 milliamp . Now a bit more math .340 milliamp flowing through 10K would be a voltage drop of 3.4 volt and the drop across the 4.7K would be 1.6 volts. So at the junction of the 4.7 K and 10K you would read 3.4 VDC. Thus one end of the 4.7K is connected to the Arduino pin the junction connection of the 4.7K and 10K is peeled off to the display and the other end of the 10K goes to ground. Instant level shifter. You would need 6 such combinations of 4.7K and 10K resistors.

Another way is to take an IC such as a hex buffer IC such as the CD4050 and by connecting 3.3 VDC to Pin 1 (Vdd) all inputs to the IC (six total) are outputted at 3.3 VDC. Many of the wing nut jobs hate this approach because it is not bi-directional. There are bi-directional level shifters but cost more than the nominal 50 cents for the CD4050. In my application I only need a single direction and that is a down shift. Below is the pin out for the CD4050

Here is the display and you will get a sense of the size with the ease of readability. Did I mention about the 256K color choices?

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So now the problem is since the CD4050 level shifter will be used --how do you hook up the display? A glib answer would be carefully! Shown below is a hand sketch of the Nano ICSP and a decode of the pins on the back of the display. Note Vcc is connected to 3.3 VDC not 5 VDC as shown on the sketch.

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So yes many will have trouble connecting the dots so the magic decoder ring is provided below. Please no inquires about how to connect the output of the Si5351 --CLK0 is the LO and CLK2 is the BFO.

Wednesday, January 18, 2017

Things that are obvious are obvious!!!!!

I receive many emails regarding some of my projects. Sitting on this end I wonder a bit about those who send the emails. Mind you I am not saying I am infallible or not subject to error; but there is a difference between asking good questions and just being lazy.

Often I resist telling the sender to turn off his soldering iron and take up knitting as a hobby. This is not snobbery; but more symptomatic that many individuals find it easier to email Pete than to look up the information.

Here is an example of what I am saying. The sender tells me that his Arduino and OLED work FB when connected to his computer; but when he connects it to his power supply it will not work. He has done this cycle several times and the next step is to email me.

Well lets think about this for a minute as the only difference in these two situations is the source of power. It has nothing to do with the code or the hardware --it works on the USB port. So then I asked what are you powering the Arduino with in your rig? The response was 5 VDC. Boom fatal error.

If this individual bothered to read Arduino 101 he would find that Massimo Banzi is clear the minimum voltage level is 7 VDC and the max is 12 VDC. Why you ask? Well there is an on board regulator where the Arduino board takes Vin or Vraw and converts it to 5VDC for use on the board and even supplies 5VDC to a pin where you can tap that for other uses. On some of the Arduino boards, with the Pro-Mini being one exception, there is even a 3.3 Volt Regulator so you can provide power for the TFT displays. On the more complex sketches I usually include a Pin diagram in the comments. Yep you guessed it --got an email asking how to connect the color TFT. I asked did you read the comments. And the answer was... they are usually too technical for me so I don't read them. Say what?

Plugging in to the USB port on your computer is essentially bypassing the regulator. All voltage regulators need a higher Vin (typically at least 1.5 Volts higher) for them to work. So this noob didn't even know the basics of the Arduino. In most of my work I use a 9 VDC or 8 VDC three terminal regulator to feed the Arduino.

Then I got asked how to wire up the Si5351 and OLED and to provide a schematic. Well here is another case where the end user is not acquainting himself with the hardware. Seems like all folks want to do is hook up wires and be there. Well If I have to research it, so should you. Guys both the Si5351 and the OLED use the I2C buss. There are four connections to each and they are simply paralleled. Yah I know easier to email Pete!

So thinking just because I know, maybe I should help, so here is a paint by numbers approach for the hookup. [Wait until you hear the punch line.] So here we are.

I didn't want to create a schematic since that presumes current end users know the How to Read a schematic. So after responding to this individual --the Punch line --"you didn't specify where you connect outputs of the Si5351". WELL folks if you read the sketch you will see that CLK0 is the LO and CLK2 is the BFO. C'mon guys --you have to do some of the work!!!!!

I don't mind answering legitimate questions; but if one has to ask how to connect to an I2C buss or what are the output pins for the Si5351 --then knitting truly might be a good hobby for you.

Saturday, January 14, 2017

A Visit with an Old Friend!

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1/17/2017 ~ Scratch built homebrew rigs!

Late in 2012, I decided to build a solid state version of the famous Collins KWM-2. This now must totally convince you that I am several corn flakes short of a full bowl. Well take a look at the masthead photo and you will see that I was successful. My KWM-4 even sports a keypad (like in the KWM-380) and two of the buttons let you up / down tune the rig. Try that with your Bitx40.

It has been some time since I last had it on the air so today was a good day to light up the old rig. The KWM-4 is QRP in that it will produce 5 watts on SSB. About now I am expecting a correction on what constitutes QRP from some of the illuminati. Anyway I have temporarily put aside the FPM5 while I noodle a low drive condition on the higher bands which may entail a redesign of the famous EMRFD driver stage. Sometimes you will find EMRFD circuits are not pantyhose where one size fits all!

For those who may not know this, my KWM-4 is a dual conversion transceiver with the 1st IF at 10.7 MHz which puts it close to the 10 MHz ham band. For me it was an easy decision and I skipped 30 Meters but since I am not a CW fan it was no loss. The second IF is at 455 kHz and uses a tubular Collins mechanical filter. There is actually a crystal filter following the 1st conversion which use a 7.5 kHz wide at 10.7 MHz for this application. This solves a problem when you up convert a 455 kHz SSB or CW signal for the subtractive mix that would put an undesired signal too close the band pass filters. Yes Virginia some real innovation in this rig. This is one of my few rigs that can actually do CW and features a separate CW oscillator that on transmit bypasses the mechanical filter. More innovation here. The KWM-4 works on 80, 40, 20 15, 17 and 10 Meters

More details of the KWM-4 are shown on my QRZ.com page under N6QW. As you will note there are many rigs on that page and so this is not just a one hit wonder!

73's

Pete N6QW

﻿Simpleceiver with an OLED

1/15/2017 ~ You Tube Video of Simpleceiver with the OLED and Si5351. This was made especially for those individuals with fancy smart phones and exotic tablets who could not open the movies below. C'mon guys I am doing all the hard work the least you could do is use a real computer to view this blog!

This video is also being provided for those who tried to put the OLED and Si5351 in a Bitx40 project and had noise problems with noise being generated by the OLED. You can decide about any noise issues after listening to this test with the Simpleceiver.

73's

Pete N6QW﻿

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Late in 2015 I developed a project called the Simpleceiver which was fully documented on this blog. The evolution of the design relied heavily of the use of LT Spice to simulate circuits and to "make" Dual Gate MOSFETs by cascading J310 JFET's. I know of several duplications of this project both in Europe and in Asia. For a display I used a 16X2 LCD.

Fast forward to today where I am now using OLED's in various projects thus the foray into retrofitting the Simpleceiver with an OLED. There are several video that are presented below and you can listen closely to the audio as there have been reports of noise issues when using the OLED's. You be the judge.

The OLED, Si5351 and the Nano offer many possibilities especially for removing analog VFO's (you know the ones that drift) from your old homebrew gear and installing the new technology. A $20 Bill will put you on that road.

Thursday, January 12, 2017

Moving on with the latest Technology!

In 2011 I fulfilled a dream of building a shirt pocket sized QRP SSB transceiver. Well actually I built two of them and the second was a diminutive 2" X 4" X 2". Both used through hole components --so no cheating with SMD. In each case the IF was 4.0152 MHz and employed a crystal switched VXO that essentially gave about 100 kHz on 20M SSB. But it was a VXO and there was not full band coverage. But nevertheless a small miracle (or so I thought) that they both worked! You can see the two versions blow.

But with new technology now available to us my next goal is to fit the larger rig with the Si5351 and an OLED display. Today I made that happen!

We now have a documented QSO with VA7LTX in Canada using the rig barefoot ( 2 to 3 watts) on 20M.

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Having proven this works I am now undertaking building a smaller board to fit in the existing case. This should incentivize you to get out the soldering iron and start building!!!!

Monday, January 9, 2017

Expanding the Bitx40 Horizon ... More Hacks!

1/10/2017 ~ I was asked what does Size 1 look like on the display?

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The frequency information is in Size 2 and the other info was in size 1. I guess it is readable but small letters. It is obvious you could pack more info on to the display. But I think I will stick with Size 2.

73's

Pete N6QW

1/9/2017 Posting

In the course of adding a few refinements to my Bitx40 OLED display, I now have found new dimensions to displaying information and some additional possibilities for the rig. In the realm of "cool factor" I now have managed to juggle information locations so I can include my call sign (N6QW) on the display.

This is not ego stuff but more of displaying pride in your homebrew rig. Well there is some ego stuff too, where it is something I did and you can too!. BTW you can adjust the print size of what is displayed and what you see is Size 2. The Size 1 selection is almost unreadable but none the less gets you "The Lord's Prayer" on the head of a pin head. Keep in mind the size of the display below is less than 1 inch on a side.

A bit more of what happens to the display and the capabilities when various modes are exercised. The display shows a 100 Hz step tuning rate which is the default setting. Engaging the Push Button located on the encoder control will step that to 1 kHz, 10 kHz, 10 Hz and then back to 100 Hz. The display will show each of these steps. Additionally when you hit the Push To Talk Switch on the Microphone the display changes the line "Bitx40" to "On the Air". When the button is released the display reverts back to "Bitx40". Pretty cool!

I feel confident these are changes that could be done to the VU2ESE supplied LCD/Arduino Nano/Si5351as the changes are in information displayed but does not disturb how frequencies are generated. So maybe someone reading this blog and has the VU2ESE board can make the changes and contact VU2ESE to include it on the hfsigs hack page.

The other aspect is the ability to tune outside of the ham bands which in this case shows a frequency of almost 33 kHz above "40 meters". This feature is good for listening only! I don't believe there is any world wide amateur operation permitted above 7.300 MHz; but there are shortwave broadcast stations that operate in this range. There are even websites that will help you locate these stations based on the frequency being read on your display.

Now before you get too excited -- typically the designs of our transceivers include Band Pass and Low Pass Filters. These filters by design limit your frequency excursions (especially on the transmit side). So tuning 30 to 50 KHz above or below 40 Meters will result in your ability to hear stations. A well designed set of filters will make it seem like the rig has gone deaf once you get slightly above or below the specific band --it should work like that!

Another limitation is what are the frequency end points set in the Arduino code. So in addition to the hardware limits (BPF and LPF) there are frequency limits typically coded into the sketch. Thus one of the hacks is to somewhat expand the lower and upper frequency limits so that the Arduino will tune either the AD9850 or Si5351 slightly above and below the 40 Meter Band.

The rig now being sold by VU2ESE includes the LCD display along with the Arduino Nano and the Si5351. I am unaware of the limits set in the code. So if you have one of the new rigs drop me an email N6QW and let me know the limits. Of course I "rolled my own" so I picked the limits.

My OLED is now being driven with an Arduino Nano (versus what I did for the original development using the Uno). One report I received from Mike WA3O who is using an OLED with his Bitx40 is that he is hearing noise generated in the OLED being induced into the Bitx40. He further advised that having a separate power supply for Arduino/OLED abated the noise generation problem. Thus I have not had the OLED in the rig but will run that test and report the results.

More refinements the 100's, 10's and 1's are displayed in a window like view of the actual frequency. Helps focus quickly where you are in the band. Another hack!

Sunday, January 8, 2017

Does anyone in Radio Land know what this is?

OK do you give up? Well guys and gals this is the world's most important tool vintage 1965 if you were in a forward combat area and wanted to eat. Yes this foldable, carry on your key chain, (along with your dog tags) is a can opener! I have had it on my key chain for the past 52 years and serves as a reminder of another time and another place.

In May of 1965 while assigned to MCB Ten (US Navy Mobile Construction Battalion Ten) as a part of the US Marine Corp RLT4 (Regimental Landing Team 4). RLT4, we made the first over the beach amphibious landing since the Korean War. It was a heady time filled with excitement as we landed on the beaches of Chu Lai, South Vietnam about 90 miles south of DaNang.

With such a landing comes combat rations (for about two months) known as MIC's which stands for Meal Individual Combat. The MIC's came in cases of 12 meals and included in every case were several of these tools and a pack of heat tabs so you could have a warm meal.

There were four selections of MIC's and included Turkey Noodle Loaf, Beanies and Weenies, Hot Ham Hunks and Hamburgers which literally were packed in axle grease. Accoutrements might include a small bread in a can along with grape jelly, cheese and crackers and the most coveted canned peaches. The cheese and crackers were actually medicinal in nature and you usually did not eat those immediately but held on to them for when you got the "Green Apple Quick Step" AKA GI Trots, AKA The Runs. Eating one portion of the cheese and crackers would plug you up quicker than any Kaopectate or Imodium! It seems like the crackers were designed so when taken with water expanded to about 10X their size --so you really felt full (bloated is more like it).﻿

Being in the "Seabee's" the first thing you learn to do is to take the can opener and using a spent can from the Beanies and Weenies (taller can) build a small stove so you can efficiently heat your food. The heat tab went in the bottom of the can and with proper vent holes cut in the can itself --instant stove. (This was my first opportunity at learning metal working skills which has paid big dividends today.)

There also was included in every MIC a small pouch that had cigarettes, toilet paper and a spork -- that was a plastic spoon with serrated teeth on the end so it was a combo spoon and fork. I think there might have been some other stuff in there but it was kind of clever. I think later on they removed the cigarettes --getting killed with bullets is just a day's work but lung cancer was not approved.

The reason for this posting was that recently I tripped over a whole series of you tube videos where individuals actually take the various combat meals and try to explain them It goes from the K Rations to C Ration to the MRE's of today. It is very obvious that the narrators never had to eat these meals. They just didn't know!

My assignment at MCB 10 was the Intelligence Officer and as such I had access to the classified safes. In the Spring of 1965 it was very obvious to me that we would be headed to South Vietnam and would transition as the alert battalion on Okinawa to an in country location. In preparation for the deployment I cleared space in one of the files so it would hold six bottles of Johnny Walker Black Label whiskey. There was some benefit to being the only one who had access to the classified safes! At the time I had a 1st Class Petty Officer working for me and he approached me about his also placing something in the classified safe. I said OK -- well as it turns out his contribution was a very small box that contained 12 bottles of what is shown below:

At first I thought he was nuts; but so be it! Well as it turned out my 1st Class Petty Officer was a veteran of the Korean war some 15 years earlier and he knew all about C rations. After a short while I traded him 3 bottles of Johnny Walker for three bottles of the hot sauce. The only way you could eat those MIC's was with hot sauce.

Being the Intelligence Officer meant I had to have special security clearances which later came back to bite me. On a second trip to Vietnam where I was TDY it bit me. I was on a commercial contract flight (DC8) that was just about to depart Travis Air Force base when I heard my name called out over the PA and was asked to come forward. There were two Air Force officers there who then asked me to show my ID card which I did. One of them then said stick out your left wrist --I did. Boom the next thing I know they slap a handcuff on my wrist an attached to that was a courier pouch. It seems like this was highly sensitive information that could only be carried by someone with the appropriate clearance.

The next couple of statements were kind of frightening where I was advised to shoot anyone who tried to get the pouch from me and he was about to hand me a gun. I said I have a 45 in my brief case but no ammo --he got me two clips. of 45 ammo. The next statement was I could not leave the plane until I was relieved of the pouch in Honolulu.

Did you ever try to snooze in a packed airplane with a pouch handcuffed to your left wrist. Going to the head for a pit stop was a barrel of laughs. The heads are really small and not much room for you AND the pouch. Well at the other end I had to wait 1 hour for someone to show up --it was not a fun trip! I keep thinking about trying to board an airplane today with a 45 in your brief case!

Friday, January 6, 2017

Still even more Hacking of the Bitx40!

1/7/2017 ~ Dress up your OLED Display!

Same code works for the Color or Black and White OLED

So there is no reason why your Bitx40 cannot have the finished feature rich appearance just like those kilobuck black boxes. Imagine that when you show off your rig to your friends you can get the OOOhs and Ahhhs and "Gee how do I do that" comment. Well you could check the EMRFD reflector but you might not find it there. QST probably doesn't have it either. But N6QW does!

Here is what I am saying! The OLED will have one display feature during receive but hit the PTT and the OLED displays something else. Release the PTT and it goes back to the normal mode. Now how cool is that?

This feature only takes a small additional modification to the hack I provided to switch in line an external linear amplifier. Yes I figured out the code kink. Email me at n6qwham@gmail.com if you would like the code snippet. So aside from the code you will two diodes and one reed relay.

Another Bitx40 hack on the drawing boards is how to remotely start the coffee pot while you are in a QSO.

As Sir Winston Churchill so aptly said KBO!

73'ws
Pete N6QW

BTW the Black and White version was the original development work for use on a 20M Transceiver. When I got it working it was a short distance to the Bitx40. Find that on EMRFD or QST?

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Yet another hack of the Bitx40!

1/7/2017 The Arduino Sketch will be posted on my website using the link below. It will be on the Phase 7 page link.

Think small and smaller! When I built my Bitx40, the display add on kit which I think now is the standard was not available. So in true ham fashion I simply "rolled my own". I thought I really got things small when I used an 8X2 backlit LCD coupled with the Pro-Mini and AD9850

Well now there is something even smaller which I have working. See below. The size is less than one inch on a side. There are four step tuning ranges and include 10, 100, 1K, and 10K Hz. I am still working out a "code kink" so that when you transmit the "Bitx40" is replaced by the message "On The Air".

With the OLED + Si5351 it should be possible to shrink even further the overall footprint of the Bitx40. Not only is the physical size smaller; but the power requirements are significantly reduced. The new configuration will have the OLED, Pro-Mini and the Si5351.

Yes I could just buy the add on kit --but the rig was designed to be hacked!!!!!